Paraffin scraper and rod guide



Oct. 17, 1961 P. POLSON PARAF'FIN SCRAPER AND ROD GUIDE Filed D60. 12,1958 m m w m m n 0 3 a; O 7 P 5 747/027 2 I 4 u i! a g P F Y B m 3. 4 EM E w VWLW x H & M 3

ATTORNEY This invention relates to oil well pumping equipment, and ithas particular reference to paraffin scrapers for 1 preventing orminimizing the accumulation of parafiin deposits on the inner surfacesof the well tubing during pumping operations.

A related device is shown in my Patent No. 2,772,741, dated December 4,1956.

An object of the invention is to provide a device which effectivelyprevents static deposits of paraffin in the tubing and affords anefiicient guide for sucker rods operating therein.

Another object of the invention is to provide a simple and economicalstructure which can be installed along the sucker rod at spacedintervals, as desired, and arranged thereon at diiferent radialpositions with respect to each other so as to insure the maximumefiiciency in operation.

Another object of the invention is to provide a parafiln scraper andsucker rod guide having a minimum of parts which reduces the cost offabricating the device and affords a structure which is not readilydestructible and is not likely to become dislodged and fall into thewell to impair the pump or hinder its operation.

Another object of the invention is to provide a paraffin scraper andsucker rod guide which is so constructed that its presence atlongitudinally spaced intervals along the sucker rod will notexcessively restrict the flow of the oil through the tubing 0runnecessarily burden the pump operating mechanism with its weight.

A further object of the invention is to provide a combined paraffinscraper and rod guide which can be so arranged and spaced along the rodas to effectively scrape the inner surface of the tubing on each strokeof the pump while at the same time preventing the rod from contactingthe tubing wall.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

FIG. 1 is a sectional elevational view, taken on a median line, showinga plurality of scraper and guide units embodying the inventionoperatively connected to a sucker rod disposed within a Well tubing;

FIG. 2 is a sectional plan view taken on the lines 2-2 of FIG. 1;

FIG. 3 is a sectional plan view taken on the lines 3-3 of FIG. 1; and

FIG. 4 is a fragmentary sectional elevational view on an enlarged scale,taken on a median line, showing a portion of the sucker rod and one ofthe scraper and guide units.

Referring to FIG. 1 of the drawing, the numeral 1 designates a welltubing. A sucker rod 2, used to operate a well pump (not shown), isarranged concentrically within the tubing 1 and is movable reciprocallytherein. A plurality of scraper and guide units embodying the invention,which are indicated generally by the numeral 3, are attached to the rod2 at longitudinally spaced intervals and slidably engage the inner wallof the tubing 1.

As shown in FIGS. 2 to 4, the scraper and guide units each include aband 4, which is split longitudinally at 5. The band 4 surrounds the rod2 and is secured thereto by press fit,

A pair of spacer bars 6 are arranged parallel to each other and to therod 2, and are rigidly secured, as by welding, to the peripheral surfaceof the band 4 on opposite sides thereof, so that their lower ends dependbelow the band 4, as shown in FIGURES l and 4. The spacer bars 6 arerectangular in transverse section, and have chisel-edged end portions 7on adjacent ends thereof for use as guides, for guiding the scraper andguide unit 3 into the tubing 1. One of the spacers bars 6 is connectedto the ban-d 4 adjacent the gap 5 thereof, whereby the gap 5 is bridged.

An annular scraper 8, which has an outside diameter approaching theinside diameter of the tubing 1, is arranged concentrically relative tothe band 4, and is rigidly connected to the spacer bars 6 opposite theband 4, as by welding. The scraper 8 loosely engages the tubing 1.

The scraper 8, which is narrower than the band 4, is initially splitlongitudinally at 9. The scraper 8 is first pressed in position aboutthe band 4 and the spacer bars 6, after which it is secured to thespacer bars 6 by welding. Finally the gap 9 of the scraper 8 is closedby filling it with weld metal and grinding the adjacent peripheralsurface of the scraper 8 to remove excess metal.

In operation, the scraper and guide units 3 are attached to the suckerrod 2, which is used to operate the well pump (not shown), and aremovable reciprocally therewith, whereby the annular scraper 8, whichloosely engages the tubing 1, is caused to scrape the inner wall of thetubing 1 free of deposits of paraflin and the like.

The scraper and guide units 3 are also operable as guides whereby thesucker rod 2 is adapted to be maintained in its concentric positionrelative to the tubing 1, independently of the curvature or inclinationof the well bore.

The spacer bars 6 maintain the annular scraper 8 in spaced apartrelation to the band 4 and the sucker rod 2, whereby spaces are providedin the annulus between the annular scraper 8 and the band 4, on oppositesides of the scraper bars 6, for the passage of well fluids uponreciprocal movement of the sucker rod 2 and the scraper and guide units3 in the tubing 1.

The chisel edged end portions 7 of the spacer bars 6 are useful asguides, for guiding the scraper and guide units 3 into the tubing 1.

The invention may be modified in various ways without departing from thespirit and scope thereof.

What is claimed is:

The combination of a well tubing, a pump rod arranged concentricallytherein and movable reciprocally thereof, and a combined parafiinscraper and rod guide unit secured to the rod and slidably engaging theinner wall of said tubing, the scraper and guide unit comprising a bandpress fitted on said rod, a pair of diametrically opposed spacer barsarranged parallel to each other and to the rod and secured to theperipheral surface of said band on opposite sides of said rod, the lowerends of said bars depending below said band, and having opposinglybevelled lower ends, and an annular scraper, narrower than said band,embracing said bars and said band, and rigidly secured to said barsopposite said band whereby the said spacer bars extend below saidscraper for guiding said unit into a well tubing.

References Cited in the file of this patent UNITED STATES PATENTS1,770,207 Helmling July 8, 1930 2,058,331 Long Oct. 20, 1936 2,244,104Fitzpatrick June 3, 1941 2,402,345 Ratigan June 18, 1946 2,702,083'Wagner Feb. 15, 1955- 2,772,741 Polson Dec. 4, 1956

